mitosis

MadNatSci

Your third question is easiest to answer I think. Firstly they add colchine to mitotically dividing cells because during mitosis the chromosomes are condensed and so you can see them. The reason they add colchine, to prevent the formation of spindle fibres, is presumably to stop the chromosomes from migrating across the cell so that you can examine them properly. It'd be a right pain to have to try to examine moving chromosomes!

In anaphase perhaps there are fewer cells to be seen because the cells expand a bit? I'm really not sure, sorry - my brain isn't working properly this evening!

Hi, MNS, do you know how fast the chromosomes migrate? Would it be seen under a light microscope? Or would oyu have to speed it up for the action to be discernible?

My reasoning for anaphase being less discerened, is perhaps that anaphase's time slice is very limited in a mitotic cell cycle, thus we see a less proportion of them in a staining prodecure.

Reply 3

MadNatSci

12

2776

Hi, MNS, do you know how fast the chromosomes migrate? Would it be seen under a light microscope? Or would oyu have to speed it up for the action to be discernible?

My reasoning for anaphase being less discerened, is perhaps that anaphase's time slice is very limited in a mitotic cell cycle, thus we see a less proportion of them in a staining prodecure.

Not very fast, in all honesty; mitosis itself takes half an hour from start to finish, so I'd imagine (this is pure, unadulterated guesswork) that anaphase takes about 15 mins. But that's fast enough to be a pain if you want to do an in-depth study of the chromosomes, so there does seem to me to be good reason to get rid of the spindle apparatus... They tend to speed the film up when they show you film of it. But having never been able to observe mitosis in a living cell (I've only seen fixed mitotic cells), I couldn't really say for sure!

edit: oh and of course!! I completely misinterpreted the question on the anaphase cells :redface:

My brain really isn't working tonight!! You're absolutely right on that one, I think :smile:

(Which may make the time course for anaphase a lot faster than 15 mins)

Reply 4

2776

Hi, MNS, do you know how fast the chromosomes migrate? Would it be seen under a light microscope? Or would oyu have to speed it up for the action to be discernible?

My reasoning for anaphase being less discerened, is perhaps that anaphase's time slice is very limited in a mitotic cell cycle, thus we see a less proportion of them in a staining prodecure.

You'd probably want to use a stain and fluorescence microscopy to look at moving chromosomes (have you seen those nice green video things?). Bright field in a light microscope usually requires the cells to be fixed and I don't know if phase-contrast would be much good.

Ben

Reply 5

shiny

12

2776

Hi, MNS, do you know how fast the chromosomes migrate? Would it be seen under a light microscope? Or would oyu have to speed it up for the action to be discernible?

My reasoning for anaphase being less discerened, is perhaps that anaphase's time slice is very limited in a mitotic cell cycle, thus we see a less proportion of them in a staining prodecure.

Get the CD-ROM that accompanies Alberts. Nice videos on there.

Reply 6

All great ideas. Will carry out them. And is Albert as in "Cell Biology" Alberts?

Reply 7

2776

All great ideas. Will carry out them. And is Albert as in "Cell Biology" Alberts?

'Molecular Biology of the Cell' Alberts, I think - the big useless silver one.

Ben

Great info, cheers

Ben.S.

'Molecular Biology of the Cell' Alberts, I think - the big useless silver one.

Ben

It may or may not be useless but it's the standard cell biology text so :redface:

Reply 10

shiny

It may or may not be useless but it's the standard cell biology text so :redface:

Standard text, where? We have a few - Stryer is far better as far as a lot of biochemistry is concerned but Alberts has pretty comprehensive coverage of development and its associated genetic bits.

Ben

Reply 11

Ben.S.

Stryer is far better as far as a lot of biochemistry is concerned

Ahh, Stryer is a classic.

Zubay & Lehinger(sp) are pretty good as well.

Reply 12

Muse

Ben.S.

Standard text, where? We have a few - Stryer is far better as far as a lot of biochemistry is concerned but Alberts has pretty comprehensive coverage of development and its associated genetic bits.

Ben

i can see stryer on my bookshelf this very minute, but am reluctant to ever open its mean green exterior.

Reply 13

timeofyourlife

i can see stryer on my bookshelf this very minute, but am reluctant to ever open its mean green exterior.

Well the blue sheen on my Stryer is ever radient. What edition is the green stryer?

Reply 14